U.S. patent application number 10/263727 was filed with the patent office on 2003-09-25 for high-density power source (hdps) utilizing decay heat and method thereof.
Invention is credited to Filippone, Claudio.
Application Number | 20030179844 10/263727 |
Document ID | / |
Family ID | 28044632 |
Filed Date | 2003-09-25 |
United States Patent
Application |
20030179844 |
Kind Code |
A1 |
Filippone, Claudio |
September 25, 2003 |
High-density power source (HDPS) utilizing decay heat and method
thereof
Abstract
This invention describes an innovative miniaturized decay-heat
engine formed by a closed-loop system powered by the spontaneous
decay of radioisotopes emitting alpha particles. Said alpha
particles are emitted inside a sealed and reinforced capsule or rod
whose surfaces reach a relatively high temperature as a result of
the capture of the alpha particles in the inner shell of said
capsule. Radiation shielding is not a significant problem since
alpha radiation is stopped by the materials encasing the capsule.
The cladding material covering the alpha capsule or rod acts as the
thermal interface and the radiation shield at the same time. This
invention provides a power source for time duration significantly
longer than any power system powered by fossil fuels with minimum
weight. The unit is assembled in an ultra-compact package providing
power from a few months to several years without need for
refueling.
Inventors: |
Filippone, Claudio; (College
Park, MD) |
Correspondence
Address: |
CLAUDIO FILIPPONE
8708 48th PLACE
COLLEGE PARK
MD
20740
US
|
Family ID: |
28044632 |
Appl. No.: |
10/263727 |
Filed: |
October 4, 2002 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60326992 |
Oct 5, 2001 |
|
|
|
Current U.S.
Class: |
376/208 |
Current CPC
Class: |
F15B 2015/208 20130101;
G21H 1/00 20130101 |
Class at
Publication: |
376/208 |
International
Class: |
G21C 007/00 |
Claims
What is claimed is:
1- A high-density scaleable power source utilizing decay heat
configured to produce electric energy and shaft work, the system
comprising: At least one or more decay-heating fuel elements; At
least one thermal hydraulic path containing said decay-heating fuel
element(s); At least one expanding fluid stored inside at least one
storage tank connected to said thermal hydraulic path; At least one
compressing pump; At least one high-pressure check-valve to allow
said expanding fluid to flow inside said thermal-hydraulic path; At
least one or more fluid injector(s); At least one clearance formed
by the outer surfaces of said decay-heat fuel element(s) and the
inner surfaces of said thermal-hydraulic path converting said
expanding fluid into superheated vapor; At least one nozzle for
said superheated vapor to expand through a vapor turbine converting
said superheated vapor into mechanical energy and vapor; At least
one closed-loop high efficiency condenser formed by surfaces cooled
by a gaseous or liquid coolant wherein said vapor condenses on
contact with said surfaces; One or more thrust bearings supporting
a drive shaft 18. At least one impeller connected to said drive
shaft; At least one alternator rotor connected to said drive shaft;
At least one said vapor turbine connected to said drive shaft; At
least one rechargeable battery; At least one mechanical coupler for
external power actuation; A gear system connected to said
mechanical coupler; At least one thermostatic valve allowing
conductive foam to cool said decay-heat fuel elements.
2- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said decay-heat fuel elements are
formed by sealed and reinforced pellets or capsules containing a
desired amount of nuclear decaying isotopes.
3- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said nuclear decaying isotopes are
formed via neutron bombardment.
4- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said nuclear decaying isotopes are
formed via ion bombardment.
5- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said nuclear decaying isotopes are
formed via chemical extraction from radioactive materials.
6- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said reinforced capsules or pellets are
packaged inside a rod containing a solution to increase heat
transfer and radiation shielding from said reinforced capsules or
pellets and said rod.
7- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said thermal-hydraulic circuit contains
said decay-heat fuel elements positioned so that between the outer
surfaces of said decay-heat fuel elements and the inner surfaces of
said thermal-hydraulic circuit there is enough clearance to allow a
fluid to expand while transiting inside said clearance.
8- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said compressing pump can be submerged
inside a storage tank positioned anywhere in the unit as long as
the suction of said pump is hydraulically connected with thermal
hydraulic circuit.
9- A high-density scaleable power source utilizing decay heat as
defined in claim 8, wherein said compressing pump is mechanically
driven by a gear system coupled with said drive shaft.
10- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said high efficiency condensers are
formed by surfaces cooled on one side by an external coolant while
its inner closed-loop surfaces allow said vapor to condense back to
liquid.
11- A high-density scaleable power source utilizing decay heat as
defined in claim 10, wherein said coolant can be gas, liquid, or
any fluid provided that the blades of said impeller are shaped
accordingly with the choice of said coolant.
12- A high-density scaleable power source utilizing decay heat as
defined in claim 10, wherein another cooling mechanism of said high
efficiency condensers is accomplished via conduction to cooling
fins positioned along the circumference of the HDPS unit.
13- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said alternator rotor contains compact
magnets magnetically coupled with stationary coils positioned in
the vicinity of said alternator rotor.
14- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said rotor can be embedded with said
vapor turbine.
15- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein the alternating magnetic field
generated by said alternator rotor and said stationary coils is
controlled by a centralized computer by means of power switching
components.
16- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said battery is charged by said power
switching components controlled by said centralized computer.
17- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said gears are mechanically connected
to a mechanical coupler.
18- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein cooling of the HDPS unit is achieved
automatically as a function of load
19- A high-density scaleable power source utilizing decay heat as
defined in claim 1, wherein said thermostatic valve allows to fill
the environment surrounding said thermal-hydraulic circuit with a
highly conductive foam kept under pressure in pressurized tank.
20- The method of extracting electric power from decay-heating
isotopes by means of a scaleable power source comprising: At least
one or more decay-heating fuel elements; At least one thermal
hydraulic path containing said decay-heating fuel element(s); At
least one expanding fluid stored inside at least one storage tank
connected to said thermal hydraulic path; At least one compressing
pump; At least one high-pressure check-valve to allow said
expanding fluid to flow inside said thermal-hydraulic path; At
least one or more fluid injector(s); At least one clearance formed
by the outer surfaces of said decay-heat fuel element(s) and the
inner surfaces of said thermal-hydraulic; At least one nozzle for
superheated vapor to expand through a vapor turbine converting said
superheated vapor into mechanical energy and discharging vapor
inside a closed loop; At least one closed-loop high efficiency
condenser formed by surfaces cooled by a gaseous or liquid coolant
wherein said vapor condenses on contact with said surfaces; One or
more thrust bearings supporting a drive shaft 18. At least one
impeller connected to said drive shaft; At least one alternator
rotor connected to said drive shaft; At least one said vapor
turbine connected to said drive shaft; At least one rechargeable
battery; At least one mechanical coupler for external power
actuation; A gear system connected to said mechanical coupler; At
least one thermostatic valve allowing conductive foam to cool said
decay-heat fuel elements. At least one said coolant inlet At least
one said coolant outlet A cooling fin system positioned and in
thermal contact with the HDPS unit.
Description
BACKGROUND OF THE INVENTION
[0001] Thermionic Generators have been widely and effectively
utilized as devices able to convert nuclear decay heat into
electricity. The principles governing these technologies relay on
thermocouple effects between junctions exposed to a temperature
differential. Several patents on these devices have been developed
over the last few decades. In order to produce significant power
these devices are quite heavy and bulky. Miniaturized devices
produce extremely low power level which might be all it is
necessary for certain applications. For example, Power Chip.TM. is
a solid-state device that uses small sandwich-like wafers to
generate electricity from a temperature differential. The
technology is closely related to Borealis proprietary Cool
Chips.TM. technology. Borealis patent, titled "Process for
Stampable Photoelectric Generator", U.S. Pat. No. 6,239,356, was
issued by the United States patent and Trademark Office on May
29th, 2001. A basic data search produced countless methods and
apparatus for thermionic converters. For example, "Method and
Apparatus for a Vacuum Thermionic converter" with thin film
carbonaceous field emission, U.S. Pat. No. 6,064,137, and several
other patents developed to decrease the work function of the
materials forming the thermocouple junction to increase the
electron efficiency. Most of these patents are centered on the
utilization of decay heat to create a temperature differential
between exotic junctions to produce electricity as efficiently as
possible. All of these technologies, although very sophisticated,
produce relatively bulky and relatively inefficient electric
generators especially when the energy demand at their output is
relatively high. The main objective of the present invention is to
entirely by-pass the conversion of decay heat into electricity via
thermocouple technologies. To achieve this objective a special heat
exchanger in conjunction with a vapor cycle and a novel automatic
cooling system for condensation is utilized to convert decay
heat-to-fluid energy-to-electricity or mechanical work. This
high-density power source is scaleable and can produce significant
power output even when the unit is miniaturized.
SUMMARY OF THE INVENTION
[0002] One or more sealed reinforced alpha decay-heated capsules or
rods assembled inside a heat transfer mechanism formed by extended
surfaces separated by a clearance become the heat source and the
radiation shield of a closed-loop vapor cycle. An organic fluid, or
any fluid with the proper thermal physical properties, is utilized
as the expanding fluid inside said clearance. Once pressurized
inside the clearance said fluid undergoes heat transfer with said
extended surfaces in thermal contact with the decay-heated capsule
or rod. The level of pressurization inside said clearance is
proportional to the amount of decay heat available from the
decaying isotopes. At this point high-pressure super-heated fluid
is allowed to expand inside a vapor turbine, thereby converting the
vapor energy into mechanical energy. Said vapor turbine is
mechanically linked to a forced air/gas or liquid cooling system in
thermal contact with compact condensers designed to condense said
fluid once expanded through said vapor turbine. When the electric
or mechanical load applied to the HDPS is minimum the decay-heated
capsule(s) or rods are automatically cooled by an increased coolant
flow forced by an air/gas compressor or liquid pump by means of an
impeller driven by said vapor turbine. The output of this engine is
shaft-work and electrical power scaleable in a manner proportional
to the amount of alpha emitting isotopes, and for a duration
proportional to the half-life of said alpha emitting isotopes.
Isotopes can be generated as a result of neutron or ion
bombardment, or they can be chemically extracted from spent nuclear
fuel. If the alpha emitting isotope is also emitting other
undesired forms of radiation such as gamma-rays or beta-rays, or a
combination of said beta and gamma-rays, the unit can be equipped
with additional shielding. Therefore, the unit is designed to
safely operate with pure or almost pure alpha emitters, but can
also be operated with isotopes having large probability of emission
in the form of alpha particles and small probability of gamma or
beta emission.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 Is a schematic representation of a cylindrical HDPS
showing a preferential but not limiting disposition of one or more
decay heated capsules or rods integrated inside a thermal-hydraulic
closed loop wherein a fluid executes a vapor cycle.
[0004] FIG. 2 Is a simplified representation of the basic steps
necessary to manufacture one capsule or rods containing a selected
isotope with a desired half-life and radiation decay mode (i.e.
alpha, beta, etc.).
[0005] FIG. 3 Is a schematic with a detailed description of the
rotating components forming the power plant of the HDPS unit along
with the cooling system.
[0006] FIG. 4 Is a schematic representation of a miniaturized
configuration of the HDPS scaleable down to the size of a "fat"
cigarette wherein all sub-components are self-contained.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0007] The working principles of the HDPS system are now described
by utilizing the schematics and representations shown in FIGS.
1-4.
[0008] In FIG. 1, one or more decay-heating fuel elements 1, formed
by sealed and reinforced pellets or capsules 1a (FIG. 2),
containing a desired amount of nuclear decaying isotopes If (FIG.
2), are positioned inside a thermal hydraulic circuit 2. These fuel
elements can be manufactured in any shape or dimension. Said fuel
element(s) 1 are positioned inside said thermal-hydraulic circuit 2
such that between the surfaces of said fuel elements 1 and said
thermal-hydraulic circuit 2 there is enough clearance to allow a
fluid to expand while transiting inside said clearance. Said fluid
is stored inside the storage tank 3 and inside the hydraulic path
of the high efficiency condenser 4. Said fluid is compressed by
pump 5, which can be submerged inside tank 3, or positioned
anywhere in the unit as long as the suction of pump 5 is
hydraulically connected with the hydraulic path indicated by number
4 in FIG. 1. Pump 5 is mechanically driven by a gear system 9
coupled with shaft 10. Once said fluid is pressurized at relatively
high-pressure check valve 6 allows said fluid to flow inside
hydraulic path 7 until it reaches one or more fluid injector(s) 8.
At this point relatively cold fluid is forced to an intimate
thermal contact with the outer surfaces of fuel element(s) 1 since
said clearance, formed along hydraulic path 2, does not allow
blankets of rapidly expanding vapor to shield the cold fluid. In
other words, all of the cold fluid injected from injector 8 is
exposed to a high heat transfer rate inside said clearance so as
that all of said cold fluid is converted into superheated vapor. At
the exit 11 of said thermal-hydraulic circuit 2 said superheated
vapor is throttled via nozzle 12 so that it can expand through
vapor turbine 13. The expanded vapor is now vented inside the
closed-loop high efficiency condenser 4 where said vapor releases
the remaining enthalpy of vaporization to the cooled surfaces of
said high efficiency condensers 4. Once enough heat has been
released said vapor condenses back to liquid fluid, thereby
resetting the condition for a new vapor cycle. The heat rejection
from the surfaces of said high efficiency condensers to the
environment is accomplished mainly by convective heat transfer
inside the coolant hydraulic path 14. This coolant indicated by
arrows 15 can be air or any fluid provided that the blades of
impeller 16 are proportionally shaped so as to add kinetic energy
and pressure to a cooling fluid whether this is in a liquid or
gaseous form. Another cooling mechanism of said high efficiency
condensers is accomplished via conduction from the inner surfaces
of path 4 to cooling fins 17 positioned along the circumference of
the HDPS unit.
[0009] In FIG. 2 a decay-heated rod 1 formed by one or more alpha
decaying capsule 1a is shown. A preferential but not limiting
manufacturing method of the decay-heated capsule is achieved by
considering a sealed capsule 1e containing an inert stable chemical
such as the element "Bismuth" 1f in a desired amount. The sealed
capsule 1e is formed by Aluminum or other materials able to
withstand the high pressure developed inside the capsule once the
materials in its inside become activated, and having extremely
short half-life once exposed to a radiation field (i.e. neutron
flux). This sealed capsule 1e is then exposed to a neutron flux 1g
inside a nuclear reactor 1h for a an amount of time proportional to
the amount of chemical 1f inside capsule 1e. The reactor 1h can be
substituted with an accelerator in which case neutrons can be
obtained through ion bombardment. After a certain time of exposure
inside a radiation field the chemical 1f is transformed into a
radioactive isotope which will decay via alpha radiation, thereby
heating the capsule 1e. At this point isotope 1ff is liquid due to
its much higher temperature. If the capsule 1e is formed by
Aluminum it will take approximately 2 days for the Aluminum to
become stable again. If the chemical 1f, once exposed to a neutron
flux, becomes a pure alpha emitter the capsule will remain at high
temperature for a time depending to the half-life of the activated
chemicals. As an example if Bismuth-209 is utilized, the consequent
alpha emitter is Polonium-210 which will decay into lead with a
half-life of approximately 140 days. The thermal output of this
isotope is approximately 140 W/g making it a remarkably compact
heat source. Once the capsule 1e made of Aluminum, or any other
material, becomes stable after the exposure inside a neutron field
it is sintered inside a reinforced metal capsule 1a. The mechanical
properties of this multi-shell capsule (or pellet) have to be able
to withstand any kind of reasonable disruptive scenario (i.e.
puncture, collision, explosion, high-temperatures etc.), since the
alpha emitting isotope is extremely toxic. All manufacturing
process must be executed by licensed operators and through the use
of robotic equipment. One or more capsule 1a can now be inserted
inside a rod 1 filled with an oil solution containing lead 1j, and
weld shut at both ends 1k. The combination of multiple capsules 1a,
scaleable in all dimensions, with the mechanical and radiation
shield formed by the rod 1 cladding, forms a multiple barrier to
rupture. The lead-oil solution 1j provides an optimum convective
heat transfer mechanism, and a radiation shield for any gamma
emitting impurities present in the chemical 1f prior irradiation.
The pressure inside this system can reach elevated levels without
jeopardizing the integrity of rod 1.
[0010] The power production system of the HDPS is described in FIG.
3. The vapor turbine 13 is mechanically linked to shaft 10 which is
supported by the thrust bearings 18. Impeller 16 and the alternator
rotor 19 are also mechanically linked to shaft 10. Rotor 19
contains compact magnets 19a magnetically coupled with stationary
coils 20. When high-pressure vapor expands through the blades of
vapor turbine 13 rotor 19 is set in motion generating an
alternating magnetic field controlled by power switching components
21 driven by a centralized computer 22. This provides a controlled
electric output utilized to charge one or more batteries 23, 24,
and 25 at different voltages. The electric output can also be
extracted from the HDPS unit without electronic control and
batteries since these components can be positioned outside the
unit. A mechanical output for mechanical actuation executable by
the unit is represented by the gear system 26a, 26b, and 26c. A
reduced low-rpm output is available at the mechanical coupler 27
while an unreduced high-rpm output is available at mechanical
coupler 28 connected to shaft 10 via shaft 10a. Cooling of the HDPS
unit is achieved as a function of load. When the electric or
mechanical load is maximum, approximately 45% of the heat is
converted into mechanical and electrical energy. The impeller 16 is
designed with blades shaped so that at this maximum load condition
the cooling fluid 15 (liquid or gaseous) provides enough mass flow
rates to extract heat from the high-efficiency condensers 4 and
reject it to the environment through concentric channel 14. When
load is absent the speed of impeller 16 increases since all of the
heat generated in the decay heated elements 1 is converted into
mechanical energy at the vapor turbine 13. Automatically a larger
mass flow of coolant 15 is forced into concentric channel 14
providing increased cooling for the excess heat. This mechanism
assures automatic cooling of the decay heating elements 1 under all
scenarios. If failures develop in any component of the cooling
circuit a thermostatic valve 29 opens filling the environment
surrounding the thermal-hydraulic circuit 2 with a highly
conductive foam kept under pressure in pressurized tank 30. Even if
tank 30 fails the heat transfer between the thermal-hydraulic
circuit 2 and the cooling fins 17 is such that the decay heated
rods 1 will remain at an equilibrium temperature which will not
jeopardize the integrity of rods 1.
[0011] In FIG. 4 a miniaturized version of the HDPS unit is shown.
In this figure one decay heat capsule la is contained inside a
cylindrical structure which can reach the dimension of a cigarette.
In this case vapor turbine 13 has a diameter in the same range of
turbine for dentist equipment. The vapor cycle operates with the
same principles described in FIG. 1. Fluid pump 5 is driven by a
gear system 9 and 9a which brings shaft power to said pump 5 via
shaft 10b. Pump 5 is submerged inside tank 3. High-pressure fluid
is pumped through fluid injector 8 inside clearance 2 heated by the
surfaces of capsule 1a. Superheated vapor flows through nozzle 12
and expands through vapor turbine 13 connected to shaft 10.
Alternator rotor 19 is also driven by shaft 10. The permanent
magnets (rare earth magnets) can also be embedded inside the
impeller 16 so that an alternated magnetic path is formed by said
magnets and stationary coils 20. Cooling fluid 15 goes through a
filter 16a and inside the high-efficiency condenser clearance 14
where said expanded vapor condenses back to liquid and accumulates
inside tank 3 again. Battery 23 is now approximately the size of a
watch battery kept charged by the alternator system driven by the
vapor turbine 13. The numbering utilized to indicate the same
components consistently with FIG. 1. This terminates the
description of the scaleable HDPS for high-density power production
without need for re-fueling or recharging for several months up to
several years depending on which isotope is selected as the fuel of
the decay heated capsule.
* * * * *